It sounds like you're going through a pretty serious depression, I would get to a psychiatrist as soon as possible. The sooner diagnosed and treated, the sooner you'll get back to normal. Take it from me, you can't just grin and bear depression, it will get worse if untreated. You would probably do well to go to your primary doctor and tell him how you've been feeling, then he will most likely refer you to a psychiatrist. Don't wait, just do it. There are a lot of good treatments out there that can help you feel like your old self again.
God bless, my friend.